JP2575763B2 - Method for producing conductive resin molded article - Google Patents

Description

The present invention relates to a method for producing an anisotropic conductive resin molded article.

[Conventional technology]

2. Description of the Related Art Conductive resin compositions have been developed for the purpose of preventing electrostatic charging, imparting easy plating properties, or imparting electromagnetic wave shielding properties. For this purpose, a conductive resin composition has been conventionally produced by adding and mixing metal powders and fibers such as aluminum and stainless steel, or carbon powders and fibers. On the other hand, conductive polymer compounds such as polypyrrole, polyfuran, polythiophene, and polyselenophene having a structure in which a 5-membered heterocyclic compound is linked to the main chain of the polymer compound show high conductivity,
As an insulator-metal transition occurs by doping and its value can be controlled arbitrarily or the optical and magnetic properties change greatly with this, it is a functional material that can be used for various functional applications utilizing this. It has received a great deal of attention.

Conventionally, these conductive polymer compounds are insoluble in all solvents and do not dissolve even by heating, so their poor processability has been a major drawback. There has been proposed a method in which a compound is synthesized and molded from a solution together with a conventional polymer compound or melt-molded to produce a conductive resin composition.

[Problems to be solved by the invention]

However, the conductive resin composition obtained by such a method has characteristics such as good dispersibility with the resin and the physical properties of the resin are not reduced. There has been a problem that the amount ratio of the polymer compound must be relatively increased.

[Means for solving the problem]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-described problems. As a result, at least one direction is stretched or rolled, and the composition of a complex 5-membered cyclic compound polymer having a specific structural unit and a thermoplastic resin is obtained. The inventors have found that the conductivity is improved and completed the present invention.

That is, the present invention relates to a thermoplastic resin represented by the general formula [I]: (In the formula [I], R ¹ and R ² are a hydrogen atom, an alkali metal atom or a hydrocarbon residue, Z ¹ and Z ² are a double bond, a triple bond, a heteroatom or an atomic group containing a heteroatom, and X is Oxygen atom,
It represents a sulfur atom, a selenium atom, a tellurium atom, an imino group, an alkylimino group or an arylimino group. k, L, m,
n is a positive integer including 0, and at least one of the sum of the number of carbons contained in R ¹ and k and m and the number of carbons contained in R ² and the sum of L and n is 3 or more. A method for producing a conductive resin molded article, characterized in that a mixture of a polymer of a 5-membered heterocyclic compound represented by the following formula and a composition containing or not containing a dopant are stretched or rolled in at least one direction. is there.

The 5-membered heterocyclic compound used in the present invention has the above formula [I]
The position of 3-position on the 5-membered heterocyclic nucleus or 3
Substituents at the 4- and 4-positions. Examples of such substituents include straight-chain alkyl groups such as propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and dodecyl, as well as cyclohexyl and cyclohexyl. Examples include a cyclic alkyl group such as octyl, and an alkyl group having a branched structure. These alkyl groups have a double bond, a triple bond, a heteroatom or an atomic group containing a heteroatom, a halogen, nitro, cyano, alkoxy, aryl, alkenyl, etc. group as shown by Z ¹ and Z ^2. May be.

Specific examples of these groups include And the like. Here, R ′, R ″ and R represent a hydrogen atom, an alkyl group or an aryl group, and R ′,
R "may be the same or different.

Here, at least one of the sum of the number of carbons contained in R ¹ and k and m and the sum of the number of carbons contained in R ² and L and n is 3
It is necessary to be above. When the above-mentioned substituent is an alkyl group having 2 or less carbon atoms, it is difficult to stretch a film of the polymer even if there are two alkyl groups, and when R ¹ and R ² are It is difficult to obtain a polymer having an alkyl group having more than 50 carbon atoms, and it is not preferable because only a film having a small electric conductivity can be obtained from the obtained polymer.

The polymer of the 5-membered heterocyclic compound used in the present invention includes:
It is usually produced by an oxidative coupling reaction of the above five-membered heterocyclic compound. Also, a method of dihalogenating the 2- and 5-positions of the above-mentioned 5-membered heterocyclic compound, reacting the substituted 5-membered heterocyclic compound with magnesium to form a diglinal, and then performing coupling polymerization using a nickel catalyst. Can also be manufactured.

Specific polymerization methods for oxidative coupling of the 5-membered heterocyclic compound include a polymerization method using an oxidizing agent catalyst and a electrochemical oxidation polymerization method. These methods are already known, for example, applied physics,
56, No. 11, (1987), p. 1433, etc. In particular, in the method of polymerizing using an oxidizing agent catalyst, a polymer can be easily obtained at low cost.

Examples of these polymerization catalysts include compounds known as Lewis acids such as aluminum chloride, iron chloride, molybdenum chloride, tungsten chloride, tin chloride, antimony chloride and arsenic pentafluoride. Of these, those having no oxidizing power such as aluminum oxide and those having low oxidizing power are preferably used in combination with an oxidizing agent such as copper oxide, manganese dioxide, or oxygen.

By adding these oxidizing agent catalysts to the substituted 5-membered heterocyclic compound represented by the formula [I], a 5-membered heterocyclic compound polymer can be easily obtained at room temperature. If necessary, adding an inert solvent to the reaction system is also a preferable method for facilitating the control of the reaction.

The composition of the present invention comprises a thermoplastic resin and the complex 5 shown above.
It is manufactured by stretching or rolling a mixture of a membered cyclic compound polymer and a composition containing or not containing a dopant in at least one direction. Here, the thermoplastic resin is not particularly limited, for example, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, polycarbonate, polyphenylene oxide, polyvinyl alcohol, polyether, polyester, cellulose resin,
Any kind of commercially available thermoplastic resin such as polyacrylamide, polyamide, thermoplastic polyimide or polyamic acid or polysulfonic acid can be used.

In the present invention, the mixing ratio of the 5-membered heterocyclic compound polymer and the thermoplastic resin can be any ratio as required. For example, when a resin composition having good conductivity is required, the amount ratio of the 5-membered heterocyclic compound polymer may be increased, and the mixing ratio of the 5-membered cyclic compound polymer and the thermoplastic resin is generally 1: It is about 99-99: 1 (weight ratio). In order to improve physical properties such as fluidity during molding and mechanical strength stability of the molded article, a suitable plasticizer may be added with a filler during molding.

As a specific method of stretching or rolling the conductive resin composition of the present invention, thermoplastic resin and complex 5 shown above are used.
In the case of using a film of a mixture of a membered cyclic compound polymer, a method of stretching by sandwiching both ends of the film with a chuck may be mentioned. In this case, it is particularly important that the temperature of the film at the time of stretching is preferably around the softening point temperature of the conductive resin composition, but the lower limit temperature may be about room temperature. The stretching speed is 1.1 to 1000 times, preferably 1.5 to 100 times, per minute. If necessary, after stretching, it is also preferable that the film is heat-fixed for a certain time within a temperature range not exceeding the softening point temperature of the conductive resin composition. When a stretched film is manufactured industrially, a known processing method such as uniaxial stretching or biaxial stretching can be used as a general method for processing a thermoplastic resin.

As another method, it is also produced by a method of rolling between rotating rollers such as rolling or calendering. In this case, the peripheral speed of the roller is 1m to 10m per minute.
00 m, preferably 5 m to 500 m. The pressure between the rollers is 1 kg to 1000 kg, preferably 5 kg to 500 kg. Also in this case, the temperature of the film at the time of stretching is preferably a temperature around the softening point temperature of the conductive resin composition, but the lower limit temperature may be about room temperature.

In the method of the present invention, the molded article is not limited to a film, and includes any form of an elongated article such as a fiber or a rod.

In the present invention, a conductive product can be produced by a step of doping the molded body thus obtained with a further appropriate dopant, if necessary. It is of course possible to mix the dopant with the composition before molding.

The dopant used here is not particularly limited, and a known dopant compound that is generally used for producing a conductive 5-membered cyclic compound polymer is used. Examples of such dopants include halogen compounds such as iodine, bromine, chlorine and iodine trichloride, protonic acids such as sulfuric acid, nitric acid, perchloric acid, and borofluoric acid, aluminum trichloride, iron trichloride, molybdenum chloride, and tungsten chloride. Acid, antimony chloride, arsenic pentafluoride, sulfur trioxide, etc., nitrosyl hexafluoroantimonate (NOSbF ₆ ), nitrosyl hexafluoroarsenate (NOAs
F ₆ ), nitrosyl trifluoromethanesulfonate (NOCF
₃ SO ₃ ), nitroyl hexafluoroantimonate (NO ₂ S
bF ₆ ), nitroyl trifluoromethanesulfonate (NO ₂
An oxidizing agent such as CF ₃ SO ₃ ); an alkali metal such as Li, Na, K, Rb, and Cs; and a tetraalkylammonium salt.

There is no particular limitation on the method of doping these dopants into the compact, and generally, the compact may be brought into contact with the dopant substance, and is often performed in a gas phase or a liquid phase. Alternatively, lithium perchlorate (LiC
l ₄ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), tetrabutylammonium tetrafluoroborate (Bu ₄ NBF ₄ ), tetrabutylammonium perchlorate (Bu ₄ NClO ₄ ) Alternatively, a method of electrochemically doping in an electrolytic solution containing an electrolyte salt such as described above may be employed.

The composition obtained in this way has an anisotropy in which the ratio of the electrical conductivity in the stretching direction to the direction perpendicular to the stretching direction is 1.1 times or more, and the electrical conductivity in the stretching direction is unstretched. It has higher electrical conductivity than that of an object.

〔Example〕

 Hereinafter, the present invention will be described specifically with reference to examples.

Synthesis Example After placing 180 g of anhydrous ferric chloride in chloroform 3 and further adding 60 g of 3-octylthiophene, the mixture was added at 30 ° C. for 1 hour.
Stir for 5 hours, add the reaction mixture to methanol 10 and stir well, then collect the insolubles by filtration, wash thoroughly with methanol, dilute hydrochloric acid, water, methanol containing aqueous ammonia, and distilled water, and reduce the pressure to 80 ° C under reduced pressure. For 10 hours, and dark green poly (3-octylthiophene) [molecular weight (in tetrahydrofuran, polystyrene standard) 146000]
50 g were obtained.

Using 3-hexylthiophene, 3-dodecylthiophene, 3-butoxymethylthiophene, 3,4-dihexylthiophene instead of 3-octylthiophene
Similarly, poly (3-hexylthiophene) [molecular weight (same as above) 293000], poly (3-dodecylthiophene)
[Molecular weight (same as above) 109000], poly (3-butoxymethylthiophene) [molecular weight (same as above) 112000], poly (3,4-
Dihexylthiophene) [molecular weight (same as above) 38000] was obtained. The electrical conductivity of each of these polymers is 10 ^-15 S
/ cm or less.

Example 1 After mixing the poly (3-octylthiophene) obtained in the synthesis example and polystyrene at a weight ratio of 1: 9 in a Henschel mixer, an extruder (BT-25, Plastic Engineering Laboratory Co., Ltd.) Manufactured), and the obtained composition is sandwiched between two iron plates having a gap of 0.1 mm at 200 ° C.
For 5 minutes to obtain a film having a thickness of 0.2 mm.

This film was cut into a width of 3 cm and attached to a thermostatic stretching machine. The distance between the chucks was 4 cm. 100 film
After heating to ° C, the film was stretched at a stretching speed of 20 times per minute so as to have a stretching ratio of 8 times. Next, the film was allowed to stand at a copper temperature for 3 minutes, cooled to room temperature, and then the film was taken out. The resulting stretched film is saturated at room temperature with iodine
After contacting for 24 hours, the electric conductivity was measured by the four-terminal method. The electric conductivity in the stretching direction was 10 ^-2 S / cm, and the electric conductivity in the direction perpendicular to the stretching direction was 10 ^-4 S / cm. Met.

On the other hand, the film before stretching is brought into contact with iodine gas having a saturated vapor pressure at room temperature for 24 hours (at this time, the electric conductivity is 10 ^-4 S / cm
Then, stretching was performed in the same manner as described above. The electrical conductivity of the obtained stretched film in the stretching direction was 3 × 10 ⁻⁴ S / cm, and the electrical conductivity in the direction perpendicular to the direction was 10 ⁻⁵ S / cm.

Examples 2 and 3 Instead of poly (3-octylthiophene) poly (3
-Hexylthiophene) or poly (3-dodecylthiophene), and stretched in the same manner as in Example 1 except that polypropylene was used instead of polystyrene. After contacting the obtained stretched film with iodine having a saturated vapor pressure at room temperature for 10 hours, the electrical conductivity was measured by a four-terminal method.
The electrical conductivity in the stretching direction is 10 ^-2 S / cm and 10 ^-3 S / cm, respectively, and the electrical conductivity in the direction orthogonal to the stretching direction is 10
^-3 S / cm and 10 ^-4 S / cm.

Example 4 Instead of poly (3-octylthiophene), poly (3
Example 1 except that -butoxymethylthiophene) was used.
Stretched in the same manner as above, the resulting stretched film was contacted with iodine having a saturated vapor pressure for 10 hours at room temperature, and the electrical conductivity was measured.The electrical conductivity in the stretching direction was ^-4 S / cm. The electrical conductivity in a direction perpendicular to the direction was 10 ^-5 S / cm.

Example 5 Instead of poly (3-octylthiophene), poly (3,
Stretching was carried out in the same manner as in Example 1 except that 4-dihexylthiophene) was used at a stretching speed of 20 times per minute so that the stretching ratio became 8 times. Then, the film was allowed to stand at the same temperature for 3 minutes, cooled to room temperature, and then the film was taken out. The resulting stretched film was contacted with iodine having a saturated vapor pressure for 10 hours at room temperature, and the electrical conductivity was measured.The electrical conductivity in the stretching direction was 10 ⁻⁵ S / cm, which was perpendicular to the stretching direction. The electrical conductivity was 10 ^-6 S / cm.

〔The invention's effect〕

The composition of the present invention has good electric conductivity and can be easily manufactured, and is extremely valuable in industry.

Claims (1)

(57) [Claims] 1. A thermoplastic resin of the general formula [I] (In the formula [I], R ¹ and R ² are a hydrogen atom, an alkali metal atom or a hydrocarbon residue, Z ¹ and Z ² are a double bond, a triple bond, a heteroatom or an atomic group containing a heteroatom, and X is Oxygen atom,
It represents a sulfur atom, a selenium atom, a tellurium atom, an imino group, an alkylimino group or an arylimino group. k, L, m,
n is a positive integer including 0, and at least one of the sum of the number of carbons contained in R ¹ and k and m and the number of carbons contained in R ² and the sum of L and n is 3 or more. A method for producing a conductive resin molded product, comprising: stretching or rolling a mixture of a polymer of a 5-membered heterocyclic compound represented by the formula and a composition containing or not containing a dopant in at least one direction.